Substrate maintenance in plant tanks is very easy. All you need to do is skim the surface of the substrate to pick up any loose debris, nothing more. The organics within the substrate benefits plants, so you want to keep that intact. I have heard of some people rebuilding their substrates every once in awhile (every few years?) to rid themselves of extra organic material, and to add more laterite (assuming you use laterite). I haven't rebuilt any of my substrates ever (I use flourite btw).
For cycling, there are two options, as you may well now. Fishless, or fishy. If you want to do a fishless cycle, don't add plants. Plants need light... ammonia + light = algae blooms. During and after your cycle, you'll be fighting some pretty nasty algae blooms if you do a fishless cycle on a planted tank.
Your second option is to do a cycle with fish. What you do is stuff your tank with as many fast growing and cheap plants that you can. Cram every square inch of your tank. Give a day or two for the plants to settle a little, then add your herbivores (ie. algae shrimp, SAEs, otos, etc.). At this stage, you must be careful not to add too many fish at once, or you might experience a small ammonia spike, which would cause algae blooms and be uncomfortable for your fish. Give your tank a month or two to establish itself, then start to slowly (a couple of fish once week) stock your tank. This stage is also very important... you must take it very slowly. If you add too many fish at once, the bacterial colonies and the plants won't be able to keep up with the ammonia produce from your fish, and it'll result in an ammonia spike. After your stocking is complete, you can start to slowly remove your plants, add other plants, begin your aquascape, etc. Be slow in this stage as well, removing too many plants at once may result in an ammonia spike (since not enough plants are around to take in the ammonia produced by the fish), so you need to be slow and allow bacterial colonies to catch up as your remove + add slower growing plants.
HTH
-Richer
